Do I fold my Jacks?

[Vee Quiva]

$55 at Party Poker. Blinds 15-30. 10 players left all with stacks between 800-1200. I have 925.

I'm in the cutoff with J [img]/images/graemlins/club.gif[/img]J [img]/images/graemlins/diamond.gif[/img]

3 folds, middle player calls 30, two folds, I raise to 90, Big Blind calls 60 and middle player calls 60.

285 in the pot and 3 players to the flop.

Flop: 10 [img]/images/graemlins/spade.gif[/img]3 [img]/images/graemlins/club.gif[/img]9 [img]/images/graemlins/club.gif[/img]

BB bets 275, Middle player calls 275.

I folded.

If one of them checks or folds, I push all it all in. When one bets the pot and the next one calls, can I assume I'm beaten?